In the next grant year, we plan to continue our investigations of the effects of polymerically bound p-chloromercuribenzoic acid and naproxen on the platelet. For the polymeric mercury compound, these studies will include investigation of the sulfhydryl groups at or near the ADP receptor site and the determination as to which sulfhydryl containing-proteins are involved with the functions of aggregation, and 5-HT uptake and release. Experiments with the polymerically bound anti-inflammatory agent will include solubilization of the prostaglandin-thromboxane synthetase to show that the polymerically bound naproxen can interact with this enzyme. Once this interaction has been established, we will undertake the purification of the enzyme by affinity partitioning. Work is also underway to prepare polymerically bound dithiothreitol, PGE1, and an epoxymethano analog of PGH2. Once these compounds have been synthesized, their effects on the platelet membrane and the aggregation process will be examined.